Cover locking carton



June 2, 1959 M. w. KUCHENBECKER 2,389,103

COVER LOCKING CARTON Filed May 20, 1957 2 Sheets-Sheet l V INVENTOR. f. 2 v MOKAIJ' k/Kl/CHENBEC/(EE BY (/fvv A TTORn/EYS June 1959 M. w. KUCHENBECKER 2, 9,

COVER LOCKING CARTON Filed May 20, 1957 2 Sheets-Sheet 2 INVENTOR. MOEP/S M KUCf/ENBEC/(EB HTTOENGYS United States Patent ice COVER LOCKING CARTON Morris W. Kuchenbecker, Neenah, Wis., assignor, by mesne assignments, to American 'Can Company, New York, N.Y., a corporation of New Jersey Application May 20, 1957, Serial No. 660,341

3 Claims. (Cl. 22945) This invention relates to improvements in covered cartons formed from paperboard or other suitable flexible material and particularly to a unique method for forming carton cover locking tabs whereby a substantial saving in material is achieved.

In the manufacture of cartons from flexible material a basically rectangular carton blank pattern ordinarily offers the greatest economy both in cutting and scoring die construction and in the waste associated with carton blank manufacture. Tabs, flaps or locking elements which protrude beyond the limits of the basic rectangle are wasteful of material and present undesirable layout problems. The carton of this invention permits maximum utilization of the construction material within the basic rectangular outline while achieving a sturdy carton construction having a simple and positive cover locking action.

Further details and advantages of the present invention will be apparent from the following specification and drawings wherein:

Figure 1 is a plan view of the outer surface of an integral blank from which the improved carton is formed;

Figure 2 is a perspective view of a fully set-up and partially open carton formed from the blank illustrated in Figure 1;

Figure 3 is a perspective view of the carton with the cover locking members partially engaged, and

Figure 4 is a perspective view of the carton in fully closed and locked condition.

For the purpose of illustrating the invention, there is shown in the accompanying drawings a form thereof which is at present preferred, since the same has been found in practice to give satisfactory and reliable results, although it is to be understood that the instrumentalities of which the invention consists can be variously arranged and organized and that the invention is not limited to the precise arrangements and organizations of the carton parts herein shown and described. The particular embodiment shown is similar in its conventional aspects to that described by Pfaif in U.S. Patent 2,652,969 and differs from the Pfafi carton mainly in the cover locking means and the associated economical use of the carton construction material.

Referring to the drawings, the carton as illustrated is made from an integral blank of paper, cardboard or the like, suitably cut and scored as in Figure 1 to provide folda ble and hingedly connected tray and cover portions, indicated generally by the numerals 5 and 6 respectively in Figure 2. The tray consists of a bottom panel 11, front wall 12, rear wall 13 and opposed side walls 14. Gluing flaps 15 are integrally connected to the rear lateral edges of the tray side walls 14 by score lines 16, and are adapted to be adhered to the tray rear wall 13 as shown in Figure 2. The tray side walls 14 are provided also with front and rear diagonal score lines 17 and 18, respectively, to permit erection and collapsing of the tray portion. Front wall 12 is provided with flaps 19 having triangular glue areas 20 adapted to be glued to the triangular segments 21 formed in the side walls by front score lines 17. When the tray portion 5 is set up from its flat collapsed position, the free, unglued portions 22 of flaps 19 will slide over the bottom panel 11 and will assume the final set-up position shown in Figure 4, whereby the tray portion is prepared for receiving goods to be packaged therein. Spaced ridges or abutments 23 in the bottom panel 11 serve to retain portions 22 of flaps 19 in set-up position.

The hinged cover portion 6 consists of a top. panel 30, opposed side walls 31 and a front wall 32. The top panel may have incorporated therein a cut-out window portion 28 for convenience in viewing the contents of the carton. The cover side walls 31 are substantially equal in height to the tray walls and are adapted to overlie snugly and completely the tray side walls when the carton is closed. The cover side walls 31 are provided with diagonal score lines 36, to permit collapsing of the cover portion to partially overlie the tray portion when likewise col-lapsed. The construction thus far detailed is conventional and well known to those versed in the art.

The cover front wall 32 is appreciably shorter than the tray walls and is thereby adapted to overlie only an upper portion of the corresponding tray front wall 12, leaving a substantial lower portion of the tray front wall exposed. The cover side walls 31. are provided with combined gluing and locking tabs 33 hingedly connected to the front lateral edges of the cover side walls. These tabs 33 are substantially co-extensive with the cover side walls in the dimension parallel to the hinge connecting the tabs with the cover side walls and, in order to permit maximum economy of the construction material, the tabs 33 must he no greater in the dimension perpendicular to the hinge than the height of the shortened cover front wall 32. Tabs 33 thereby are adapted to underlie partially the cover front wall 32 and be adhered thereto and to extend partially beyond the bottom edge of the cover front wall. The extended and exposed portions of the tabs 33 have hook-like male locking members 34 formed thereon, which may be forced to enter into locking engagement with corresponding female locking slots 35, suitably positioned in the front tray wall 12, when the cover is closed over the tray.

The shortening of the cover front wall 32 and the positioning of the male locking elements on the gluing and locking tabs 33, which have dimensions limited as previously described, result in manifold advantages. As the cover of the carton is closedover the tray portion, thernale locking elements 34 extend below the bottom edge of the cover front wall 32 and hence readily may be forced, either manually or mechanically, into locking engagement with the corresponding female slots 35. Furthermore, the shortening of the cover front wall 32 results in an appreciable saving in carton construction material while not in any way detracting from the size, appearance, strength or utility of the carton. The economy of material thus achieved is maintained by constructing the gluing and locking tabs 33 from material Within the area bounded by the outer edges of the tray and cover side walls 14 and 31 and the cover front wall 32. Such ingenious utilization of the construction material results in the greatest possible economy in manufacturing.

The degree to which the cover front wall 32 may be shortened may vary within certain practical limits. The shorter this wall is, the greater the economy of material and the more readily operable are the locking elements. It will be apparent from the drawings, however, that as the cover front Wall is shortened, the tabs 33 must also be narrowed if the material economy so achieved is to be maintained. This reduces the glue area and the maximum size of the male locking elements 34 and forces the locking areas closer to the outer lateral edges of the tray front panel 12. Consequently, the height of the cover front wall should be maintained within the obvious practical limits.

Numerous modifications may be made in the carton construction previously described and the above described embodiment is to be considered merely exemplary, although preferred. One obvious modification comprises a carton formed from a single blank and having a tray portion with attached hinged cover portion in which the two cover side walls are made shorter than the corresponding. tray walls and a locking and gluing tab is provided on each lateral edge: of the cover front wall. These tabs then partially underlie and are adhered to the cover side walls, the extended portion of the tabs having male locking members which engage corresponding female members positioned on opposing tray side walls when the carton is brought into a closed and locked condition. Substantial economies in carton construction material may be achieved using this procedure, although the layout of cutting and scoring, dies is more complex than in the preferred embodiment previously described. Another obvious modification is the provision of this material-saving, cover locking arrangement on a two-piece carton, the cover portion being separate from the tray portion as shown in US. Patents No. 2,652,969 and No. 2,713,963. In such modification, two opposed cover walls are made shorter than the remaining two cover walls, locking and gluing tabs having male. locking members are formed on both lateral edges of the two longer cover walls and female locking, slots are properly positioned in the two opposed tray sides overlain by the shorter cover walls so as to engage the male locking elements extending below the shortened cover walls.

It is desired that the present embodiment be considered in all respects illustrative and not restrictive, reference being had to the appended claims rather than to the description to indicate the scope of this invention.

I claim:

1. A carton of flexible material comprising a tray having a bottom panel, upstanding front, rear and opposed side walls and a cover having a top panel and front and opposed side walls hingedly attached to the edges of said cover top panel, said cover walls being adapted to overlie snugly the corresponding tray walls when the carton is closed, at least one of said cover walls being substantially shorter than the corresponding upstanding tray wall and the remaining cover walls and adapted thereby to overlie an upper portion of said traywall and have a substantial lower portion thereof exposed, a gluing and cover locking tab hingedly connected to a lateral edge of a cover wall adjacent to the shorter of said cover walls, the dimension of said tab parallel to its hinge connection being substantially equal to the height of the. cover wall to which it is hingedly attached, and the dimension perpendicular to its hinge connection being at most equal to the height of the shorter of said cover walls, saidv tab being adhesively secured to an adjacent shorter cover wall and extending in part beyond the lower edge thereof, the extending portion of said tab having a male locking member formed thereon, the corresponding tray wall overlain by such tab having a corresponding female locking slot positioned to engage the male locking member when the carton is closed, thereby maintaining the carton in a closed and locked position.

2. A carton of flexible material comprising a tray having a bottom panel, upstanding front, rear and opposed side walls and a cover having a top panel and front and opposed side walls hingedly attached to edges of said top panel, the cover walls being adapted to overlie snugly the correspondin" tray walls when the carton is closed, the lateral edges of the cover front wall being situated adjacent to corresponding lateral edges of said cover side walls, at least one of said cover walls being shorter than a corresponding upstanding tray wall and the remainder of said cover walls, tabs extending from and hingedly attached to the lateral edges which are adjacent to the shorter of said cover walls, the dimension of said tabs parallel to their hinge connections being substantially equal to. the height of the cover walls to which the tabs are attached, and the dimension perpendicular to their hinge connections being at most equal to the height of the shorter of said cover walls, said tabs being adhesively secured to the shorter of said cover walls and extending in part beyond the lower edge thereof, the extended portions of said tabs having male locking members formed thereon, the tray walls overlain by said tabs having corresponding female locking slots positioned to engage the male locking members when the carton is closed, thereby maintaining the carton in a closed and locked position.

3. A carton of flexible material comprising a tray having a bottom panel, upstanding front, rear and opposed side walls and a cover hingedly connected to the upper edge of said tray rear wall, the cover including a top panel and front and opposed side walls, the cover walls being adapted to overlie snugly the tray front and side walls when the carton is closed, the cover front wall being substantially shorter than the cover side walls and tray walls and thereby adapted to overlie an upper portion of said tray front wall and have a substantial lower portion thereof exposed, said cover side walls having extending gluing and locking tabs hingedly attached to their forward lateral edges, the dimension of said tabs parallel to their hinge connections being substantially equal to the height of said cover side walls and the dimension of said tabs perpendicular to their hinge connections being at most equal to the height of said short cover front wall, said tabs being adhesively secured to said cover front wall and extending in part beyond the lower edge thereof, the extended portions of said tabs having male looking members formed thereon, the tray front wall having corresponding female locking slots positioned to engage the male locking members when the carton is closed, thereby maintaining the carton in a closed and locked condition.

References Cited in the file of this patent UNIT ED STATES PATENTS 1,174,605 Palmer May 7, 1916 2,652,969 Pfatf Sept. 22, 1953 2,678,153 Buttery May 11, 1954 

